Method for renovating bowling pins



y 1950 A. SPINDT 2,506,521

METHOD OF RENOVATING BOWLING PINS Filed May 22, 1946 2 Sheets-Sheet 1 May 2, 1950 A. E. SPINDT 2,505,521

man-10v 0F RENOVATING BOWLING PINS Filed May 22, 1946 2 Shets-Sheet 2 fiatented May 2 1956 UNITED STATES PATENT OFFICE METHOD FOR RENOVATING BOWLING PINS Alvin E. Spindt, Hammond, Ind. Application May 22, 1942;, Serial No. 671,641

1 Claim.

This invention relates to a method and apparatus for renovating bowling pins after they have been used and require repairing and concerns itself with a method and means for removing the old lacquer from the pins in a speedy and eflicient manner and re-cutting the bottoms of the pins in a manner that will more efiectively maintain stability and then relacquering the treated pins.

It is Well known that bowling pins are subjected to severe usage through impacts with the bowling balls which chip the pins and knocks off parts of the coating lacquer. In addition, the tumbling of the pins causes the bottoms to become somewhat bevelled so that they lose stability. After about two weeks use the pins require a renovating process before they can be used again.

It has been customary in the past to shave off the old lacquer by suitable tools and apply fresh lacquer. This, however, involves much labor and time and proved costly. Besides the diameter of the pins would often be reduced so that they would drop through the pinsetting machines. This causes delay and loss.

It is an object of this invention to overcome this slow and costly process in renovating pins by a process which is capable of scouring as many as thirty pins at one time in a single tumbler and producing a roughened or pitted surface to which fresh lacquer will stick, and in cutting the bottom to provide greater stability. This process approximately doubles the life of the pins and greatly reduces the cost of renovation.

The invention comprises the novel method and apparatus hereinafter described and more particularly pointed out and defined in the appended claim.

In the accompanying drawing which illustrates novel apparatus for carrying out the process in which similar reference numerals refer to similarfeatures in the different views:

Fig. 1 is a front elevational view of a tumbler for carrying out the main part of this invention;

Fig. 2 is an end elevational view of the said apparatus;

Fig. 3 is an elevational view of a new bowling pin before it has been put to use;

Fig. 4 is an elevational view of a pin with the lacquer shaved off in the process of renovating the pin according to the old method;

Fig. 5 is an elevational view of a pin from which the lacquer has been removed according to my novel method;

Fig. 6 is a view of a bowling pin that has been re-lacquered and is ready for use again;

" for recutting the bottom of the pins according to Fig. 7 is an elevational view of an apparatus this invention;

Fig. 8 is a top plan view of the cutter used in I the apparatus;

Fig. 9 is an elevational view of the cutter showing the slope of certain cutting elements; and

Fig. 10 is a fragmentary sectional view of a bowling pin illustrating a stabilizing bottom.

In referring now to the drawing, there is shown in Figs. 1 and 2 a tumbling machine in which a 1 This machine 0r apparatus comprises a frame composed of end scouring of the pins takes place.

standards I I connected by lower transverse braces I2 and upper transverse braces I3. Extending inwardly of the center of the lower braces I2 are stub shafts I4 upon which a cylinder or tumbler I5 is journalled which is provided with suitable This cylinder or 1 bearing I6 for the stub shafts. tumbler which is closed at its ends is similar in shape to a barrel and might be called barrel:

shaped in order to cause a better tumbling of the pins. Within the tumbler there is fixed a rod I! the ends of which may be secured by suitable blocks Ila upon the inner sides of the ends of the tumbler which blocks may be provided with sockets to receive the ends of the rod I'I. While this rod is shown concentric of the tumbler, it may be eccentrically positioned.

Adjacent the ends of the tumbler and surrounding the same, are grooved pulleys I B, one

. adjacent each end of the tumbler. A belt I9 surrounds each pulley I9 and these belts are trained over pulleys 20 secured upon a shaft 2I journalled in the upper cross braces I 3. One end of the shaft extends beyond the frame and supports a pulley 22 I which is connected by a belt 23 with a pulley 24 on a motor shaft 25 extending from a motor 26 supported upon a platform 2'! secured to the frame. The tumbler may be provided with a suitable door or gate 28 for insertion and removal of the pins. These belt drives I9 support, the tumbler and eliminate vibrations; the stub shafts merely serving as guides.

pin has been in use several weeks.

been applied.

After the pins have been given the first treatment in the tumbler, it may be desirable to cut the bottoms thereof to cause stabilization. In

a bowling pin. 30.

Figs. 7 to 9, there is shown a simple mechanism for performing this operation. In these figures, there is shown an abbreviated lathe consisting of a base 32 having a support 33 at one end through which an adjustable screw 34 extends which is provided with an operating crank 35. Upon the inner end of the screw, there is a parti-spherical socket member 36 for embracing the top end of This socket member is preferably swivelled upon the end of the screw so that the screw can be rotated relative thereto.

At the other end of the base,v there is a motor. 31 having a shaft 38 to which a cutter 39 is coupled through a coupling 40. This cutter comprises a circular block of wood having a shaft 4| extending therethrough. One end Ma of the shaft is coupled to the motor shaft while the other end terminates in a tapered portion Mb dapted to ext nd into the cylindrical socket or passage. 42 rovided in the center of the bottomportion of the pins. 7

The; forwardface of the cutting blo k: is provided with two level saw-toothed cutting elements which are parallel and arranged upon pp site s es of the center'- They maye t in: grooves cut in the face of the block and are designed to cut a central and level recess 44 in thebottomf th p ns a sh Wn-inFig, 10. Thelength ofthese'knives '43 approximate one inch. From the'endi of one cutting knife 43, there extends a sloping saw toothedknife 45 which ex tendszbeyond theother knife 43to. a point adiacent the p phery of; hey block nd from the end of the other knife 43-, there extends a second sloping saw-toothed knife 45, which extends beyondthe first: knife a oi djacent the periphery of h lock. The. knives 45v ap proximate one and a half inches in length andare designed to cut aslopine portion 6 ar un the recess 44'. The slope; of-the khivcs flfishould be approximately two degrees from. a vertical plane asshown in Fig.9. These saw' teethknives' produce av somewhat roughed bottom on: the

bowling pins which tends toward reater sta-. bility.

-To..cut: the bottom of a pin, it'isonly neces a y to i r the sameinthe lath as sh wn and; described and start the. motor, he knives 413. cutting the central. recess 44 and-thelmive 45 cuttingthe. outwardly. slooping surface Othertion;4&. If the pin tends to rotateitmaybeheld byuthe attendant or a vise "may. be used.

sloping portion provides a better wearin surface; upon the=bottom of thepins and prevents the formation of rounded. or:bevelled edgeswhich cause-the'pinsto tumble'over too easily when in.

use-or-when being setup bypin setters.

According to my methodor process,-. abou six;

quarts of silica sand ispla'ced in the-tumbler and one-to. two pints of a. lacquer solvent, such,- as

three hours. The carbon tetrachloride softensand tends to dissolve thev lacquer on the pins during; rota e m i t sand. sticks to r t e pins so that they become sanded. Andas these sandedpins rub against each otherduring the tumbling, process, one abradesthe: lacquer from.

nother; However. thezn ck 'of hei'p n do not rub against each other very often so as to abrade Then the I the lacquer from the necks of the sanded pins, special means must be provided in the tumbler. In the present instance, the rod I1 serves such a purpose. In tumbling, the necks of the pins will ride over the rod as indicated by the pins 393a in Fig. 1 and the lacquer will be abraded from the pins. This process removes the first or original coat oflacquer.

After the pins have been tumbled for from two to three hours, they are removed from the tumbler, at which time they will have a coating or bloom of dust particles made up of lacquer as shown by the pin in Fig. 5. This sand tumbling process also puts a pebble or pit finish on the pinsv and such a surface retains the fresh lacquer and prevents the same from cracking and lengthens the life of the pins.

After the sanding operation, the bottoms of the pins are out in the lathe. as; previously explained to provide the central. recess; 44 and the two-degree sloping surface 46. During this bottom cutting with the saw-toothed knives a cer tain amount of burring occurs.

Af er he bottomsofthe pins have been out as above explained to obtain better stabilization. they are returned to the. tumbling apparatus in which about a half bushel of saw dust has now been. placed. Green sawdust is preferable,

but if dry sawdustis used. it should be moistened.

Then about a quarter apetroleum base such'asgasolineor naphtha; or any suitable solvents-that will'enter the pits. in the, pins ispoured over the;

saw dust, producingra saW-dustbath. The motor is thenput in operationto rotate the tumbler at approximately thirty. tdfifty R. P. M. for a period of fifteen to twenty minutes. This tum bling in a sawdust. bathwilLremove the burring that occurred from the cutting operation and will remove the bloom or dust. particles on the-v pinsthat resulted from the sanding eperationand' It -doubles the life ofthepins-since the sandingoperationproduces a pitted surface that will more effectively retain the freshlacquer and prevent hesame ir mr racking and since the manner ofcutting the bottom.producesfastabilizedbasethat will endure. In fact, it hasbeenfoundinprao time that; pins withebottoms out-square accord-- I s. to former. practieewiill notendure for anysuitable length of time before they wilLtopple-and fall: On the other hand; pins fashioned-with bot"- cm asherein will e du 88. 1 5; as he pins lastand provide satisfac ry stabilization A f r that miehtbe-stressedis.thesandins oper ti n which produces: a-pittedsurface. that isv a surface with. small holesior dents: in the surface of the pins; Whernpins withsuch a surface are covered with lacquer, thelacquer ntershe hi s or cavities-res lting from h sanding operation .andbecomesfirmlybonded; to thepins. In fact, itbecomes so strongly bonded thatlit cannot be scraped-- off with a-outtingtool" without cutting; away some; of: the: wood. The

lacquer could be readily scrapped away with a cutting tool from pins generally used in the past,

but that was a slow and costly operation:

' i I-am aware'thatmany changes may be made and various. details of. construction varied respecting the apparatus and the steps of the method may be varied without departing from the principles of this invention, so I do not propose limiting the patent granted thereon otherwise than necessitated by the appended claim.

I claim as my invention:

The herein described steps in the method of renovating used lacquer coated bowling pins which consists in tumbling said pins in a silica sand bath containing a lacquer solvent, supporting a rod in the tumbling area for engaging the necks of the pins during the tumbling thereof, continuing said tumbling operation until the lacquer is substantially removed from said pins, then tumbling said pins in a bath of sawdust moistened with a petroleum base for cleansing 15 the same.

ALVIN E. SPINDT.

6 REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date Re. 21,432 Lupo Apr. 23, 1940 673,665 Staley May 7, 1901 1,585,123 Sheldon May 18, 1926 1,621,780 Hirsch et al Mar. 22, 1927 1,635,472 Geiser July 12, 1927 1,644,530 Johnson Oct. 4, 1927 1,736,846 Cole et a1 Nov. 26, 1929 1,913,979 Farrington June 13, 1933 2,086,938 Hess July 13, 1937 2,357,458 Clough Sept. 5, 1944 

